glibc/sysdeps/x86_64/memrchr.S
H.J. Lu 7395928b95 x86_64: Remove redundant REX bytes from memrchr.S
By x86-64 specification, 32-bit destination registers are zero-extended
to 64 bits.  There is no need to use 64-bit registers when only the lower
32 bits are non-zero.  Also 2 instructions in:

	mov	%rdi, %rcx
	and	$15, %rcx
	jz	L(length_less16_offset0)

	mov	%rdi, %rcx		<<< redundant
	and	$15, %rcx		<<< redundant

are redundant.

	* sysdeps/x86_64/memrchr.S (__memrchr): Use 32-bit registers for
	the lower 32 bits.  Remove redundant instructions.
2017-06-05 07:41:26 -07:00

381 lines
5.9 KiB
ArmAsm

/* fast SSE2 memrchr with 64 byte loop and pmaxub instruction using
Copyright (C) 2011-2017 Free Software Foundation, Inc.
Contributed by Intel Corporation.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <sysdep.h>
.text
ENTRY (__memrchr)
movd %esi, %xmm1
sub $16, %rdx
jbe L(length_less16)
punpcklbw %xmm1, %xmm1
punpcklbw %xmm1, %xmm1
add %rdx, %rdi
pshufd $0, %xmm1, %xmm1
movdqu (%rdi), %xmm0
pcmpeqb %xmm1, %xmm0
/* Check if there is a match. */
pmovmskb %xmm0, %eax
test %eax, %eax
jnz L(matches0)
sub $64, %rdi
mov %edi, %ecx
and $15, %ecx
jz L(loop_prolog)
add $16, %rdi
add $16, %rdx
and $-16, %rdi
sub %rcx, %rdx
.p2align 4
L(loop_prolog):
sub $64, %rdx
jbe L(exit_loop)
movdqa 48(%rdi), %xmm0
pcmpeqb %xmm1, %xmm0
pmovmskb %xmm0, %eax
test %eax, %eax
jnz L(matches48)
movdqa 32(%rdi), %xmm2
pcmpeqb %xmm1, %xmm2
pmovmskb %xmm2, %eax
test %eax, %eax
jnz L(matches32)
movdqa 16(%rdi), %xmm3
pcmpeqb %xmm1, %xmm3
pmovmskb %xmm3, %eax
test %eax, %eax
jnz L(matches16)
movdqa (%rdi), %xmm4
pcmpeqb %xmm1, %xmm4
pmovmskb %xmm4, %eax
test %eax, %eax
jnz L(matches0)
sub $64, %rdi
sub $64, %rdx
jbe L(exit_loop)
movdqa 48(%rdi), %xmm0
pcmpeqb %xmm1, %xmm0
pmovmskb %xmm0, %eax
test %eax, %eax
jnz L(matches48)
movdqa 32(%rdi), %xmm2
pcmpeqb %xmm1, %xmm2
pmovmskb %xmm2, %eax
test %eax, %eax
jnz L(matches32)
movdqa 16(%rdi), %xmm3
pcmpeqb %xmm1, %xmm3
pmovmskb %xmm3, %eax
test %eax, %eax
jnz L(matches16)
movdqa (%rdi), %xmm3
pcmpeqb %xmm1, %xmm3
pmovmskb %xmm3, %eax
test %eax, %eax
jnz L(matches0)
mov %edi, %ecx
and $63, %ecx
jz L(align64_loop)
add $64, %rdi
add $64, %rdx
and $-64, %rdi
sub %rcx, %rdx
.p2align 4
L(align64_loop):
sub $64, %rdi
sub $64, %rdx
jbe L(exit_loop)
movdqa (%rdi), %xmm0
movdqa 16(%rdi), %xmm2
movdqa 32(%rdi), %xmm3
movdqa 48(%rdi), %xmm4
pcmpeqb %xmm1, %xmm0
pcmpeqb %xmm1, %xmm2
pcmpeqb %xmm1, %xmm3
pcmpeqb %xmm1, %xmm4
pmaxub %xmm3, %xmm0
pmaxub %xmm4, %xmm2
pmaxub %xmm0, %xmm2
pmovmskb %xmm2, %eax
test %eax, %eax
jz L(align64_loop)
pmovmskb %xmm4, %eax
test %eax, %eax
jnz L(matches48)
pmovmskb %xmm3, %eax
test %eax, %eax
jnz L(matches32)
movdqa 16(%rdi), %xmm2
pcmpeqb %xmm1, %xmm2
pcmpeqb (%rdi), %xmm1
pmovmskb %xmm2, %eax
test %eax, %eax
jnz L(matches16)
pmovmskb %xmm1, %eax
bsr %eax, %eax
add %rdi, %rax
ret
.p2align 4
L(exit_loop):
add $64, %edx
cmp $32, %edx
jbe L(exit_loop_32)
movdqa 48(%rdi), %xmm0
pcmpeqb %xmm1, %xmm0
pmovmskb %xmm0, %eax
test %eax, %eax
jnz L(matches48)
movdqa 32(%rdi), %xmm2
pcmpeqb %xmm1, %xmm2
pmovmskb %xmm2, %eax
test %eax, %eax
jnz L(matches32)
movdqa 16(%rdi), %xmm3
pcmpeqb %xmm1, %xmm3
pmovmskb %xmm3, %eax
test %eax, %eax
jnz L(matches16_1)
cmp $48, %edx
jbe L(return_null)
pcmpeqb (%rdi), %xmm1
pmovmskb %xmm1, %eax
test %eax, %eax
jnz L(matches0_1)
xor %eax, %eax
ret
.p2align 4
L(exit_loop_32):
movdqa 48(%rdi), %xmm0
pcmpeqb %xmm1, %xmm0
pmovmskb %xmm0, %eax
test %eax, %eax
jnz L(matches48_1)
cmp $16, %edx
jbe L(return_null)
pcmpeqb 32(%rdi), %xmm1
pmovmskb %xmm1, %eax
test %eax, %eax
jnz L(matches32_1)
xor %eax, %eax
ret
.p2align 4
L(matches0):
bsr %eax, %eax
add %rdi, %rax
ret
.p2align 4
L(matches16):
bsr %eax, %eax
lea 16(%rax, %rdi), %rax
ret
.p2align 4
L(matches32):
bsr %eax, %eax
lea 32(%rax, %rdi), %rax
ret
.p2align 4
L(matches48):
bsr %eax, %eax
lea 48(%rax, %rdi), %rax
ret
.p2align 4
L(matches0_1):
bsr %eax, %eax
sub $64, %rdx
add %rax, %rdx
jl L(return_null)
add %rdi, %rax
ret
.p2align 4
L(matches16_1):
bsr %eax, %eax
sub $48, %rdx
add %rax, %rdx
jl L(return_null)
lea 16(%rdi, %rax), %rax
ret
.p2align 4
L(matches32_1):
bsr %eax, %eax
sub $32, %rdx
add %rax, %rdx
jl L(return_null)
lea 32(%rdi, %rax), %rax
ret
.p2align 4
L(matches48_1):
bsr %eax, %eax
sub $16, %rdx
add %rax, %rdx
jl L(return_null)
lea 48(%rdi, %rax), %rax
ret
.p2align 4
L(return_null):
xor %eax, %eax
ret
.p2align 4
L(length_less16_offset0):
test %edx, %edx
jz L(return_null)
mov %dl, %cl
pcmpeqb (%rdi), %xmm1
mov $1, %edx
sal %cl, %edx
sub $1, %edx
pmovmskb %xmm1, %eax
and %edx, %eax
test %eax, %eax
jz L(return_null)
bsr %eax, %eax
add %rdi, %rax
ret
.p2align 4
L(length_less16):
punpcklbw %xmm1, %xmm1
punpcklbw %xmm1, %xmm1
add $16, %edx
pshufd $0, %xmm1, %xmm1
mov %edi, %ecx
and $15, %ecx
jz L(length_less16_offset0)
mov %cl, %dh
mov %ecx, %esi
add %dl, %dh
and $-16, %rdi
sub $16, %dh
ja L(length_less16_part2)
pcmpeqb (%rdi), %xmm1
pmovmskb %xmm1, %eax
sar %cl, %eax
mov %dl, %cl
mov $1, %edx
sal %cl, %edx
sub $1, %edx
and %edx, %eax
test %eax, %eax
jz L(return_null)
bsr %eax, %eax
add %rdi, %rax
add %rsi, %rax
ret
.p2align 4
L(length_less16_part2):
movdqa 16(%rdi), %xmm2
pcmpeqb %xmm1, %xmm2
pmovmskb %xmm2, %eax
mov %dh, %cl
mov $1, %edx
sal %cl, %edx
sub $1, %edx
and %edx, %eax
test %eax, %eax
jnz L(length_less16_part2_return)
pcmpeqb (%rdi), %xmm1
pmovmskb %xmm1, %eax
mov %esi, %ecx
sar %cl, %eax
test %eax, %eax
jz L(return_null)
bsr %eax, %eax
add %rdi, %rax
add %rsi, %rax
ret
.p2align 4
L(length_less16_part2_return):
bsr %eax, %eax
lea 16(%rax, %rdi), %rax
ret
END (__memrchr)
weak_alias (__memrchr, memrchr)